It is well known to utilize a C-shaped retaining ring capable of being spread and inserted over the end of a shaft and released into a groove around the shaft. The dimensions of both the retaining ring and the groove in the shaft are dependent upon the allowable working stresses to which the retaining ring is subjected, and it is essential that during spreading of the ring during installation that the stresses thereon do not exceed the elastic limit.
Retaining rings having either a rectangular or circular cross sectional shape are conventionally used by the industry to prevent axial displacement of a bushing, for example, on a cylindrical shaft. Unfortunately, the rings with a circular cross section are seated in relatively shallow semi-circular grooves so that the amount of force that can be resisted is lowered substantially. Furthermore, the leading sharp internal edge of the bushing has a tendency to dig into these round rings so that excess axial movement of the associated members occurs or excess deformation of the ring can result in a failure thereof.
On the other hand, those retaining rings or keepers that have a rectangular cross section provide a more positive shoulder in a plane transverse to the central axis thereof as may be noted by reference to FIG. 5. In the usual construction illustrated by FIG. 5, axial loads are transmitted through the retaining ring to the opposite face of the groove. The root corners of the groove are relatively sharp in order to relatively closely receive the sharp-edged rectangularly sectioned retaining ring. Accordingly, when the forces upon the opposite shoulder or wall of the groove exceed a particular value the stresses rise at the relatively sharp-edged base thereof to the point of failure of the retaining system. Particularly, when it is a necessity that the groove be positioned axially close to the end of the shaft because of space limitations or the like, it has been found that the failure under high loads is in the form of a shear failure of the end of the pin. As shown in FIG. 5, the shear failure is generally along a converging cone outwardly from the axially outer base edge of the groove, as indicated.
In view of the above, it would be advantageous to provide a keeper assembly better able to secure a first member against axial displacement with respect to a second member, and positively able to transmit higher loads without failure.